Users of Google who put extremist-related entries into the search engine are to be shown anti-radicalisation links under a pilot programme, MPs have been told by an executive for the company. The initiative, aimed at countering the online influence of groups such as Islamic State, is running alongside another pilot scheme designed to make counter-radicalisation videos easier to find

The schemes were mentioned by Anthony House, senior manager for public policy and communications at Google, who was appearing alongside counterparts from Twitter and Facebook at a home affairs select committee hearing on countering extremism. “We should get the bad stuff down, but it’s also extremely important that people are able to find good information, that when people are feeling isolated, that when they go online, they find a community of hope, not a community of harm,” he said.

Referring to the use of online counter radicalisation initiatives, House said: “This year…. we are running two pilot programmes. One is to make sure that these types of videos are more discoverable on YouTube. The other one is to make sure when people put potentially damaging search terms into our search engine.. they also find this counter narrative.”

Google has said that House was referring to a pilot scheme to enable NGOs to place counter-radicalisation adverts against search queries of their choosing.

A spokesperson said: “The free Google AdWords Grant program is starting a pilot for a handful of eligible non-profits organizations to run ads against terrorism-related search queries of their choosing.”

All three representatives from Google, Twitter and Facebook were challenged by MPs about the extent of their companies’ roles in combating the use of social media by groups such as Isis for propaganda and recruitment purposes.

Committee chairman Keith Vaz asked how many people are in the sites’ “hit squads” that monitor content. He was told Twitter, which has 320 million users worldwide, has “more than 100” staff. The Facebook and Google executives did not give a number.

Simon Milner, Facebook’s policy director for UK and Ireland, Middle East, Africa and Turkey, said that the site has become a “hostile place” for Isis: “Keeping people safe is our number one priority. Isis is part of that, but it’s absolutely not the only extremist organisation or behaviour that we care about.” He added that Facebook recognised from research that people did not typically get radicalised exclusively online – rather, it was a combination of real-world and online contact – and was working as a result with groups in society such as Imams.

The three were also questioned about the thresholds they apply on notifying authorities about terrorist material identified by staff or users. Labour MP Chuka Umunna asked: “What is the threshold beyond which you decide ... that you must proactively notify the law enforcement agencies?”

House and Milner said their threshold was “threat to life”, while Nick Pickles, UK public policy manager at Twitter, told the MPs: “We don’t proactively notify. Because Twitter’s public, that content is available, so often it’s been seen already.”

Pickles also stressed that decisions on whether to notify account holders that they were under investigation were “context specific” and insisted that Twitter worked with authorities to ensure that they do not disrupt investigations.

• This article was amended on 3 February 2016 to clarify Google’s counter-radicalisation initiatives and to expand a quote from Anthony House and add a response from Google.